Rotary printing press



Dec. 3, 1963 H. J. SEEL ROTARY PRINTING PRESS Original Filed April 29, 1959 m T. w m

L E x J m n w H her-h 6 3,ll2',hs Fatented Dec. 3., i963 5,112,695 ROTARY iRlNTlNG Howard 5. Seel, (Ihagrin Falls, Ohio, assignor to Harrislntertype Corporation, (Jieveland, Ohio, a corporation of Delaware ontinnation of application Ser- No. $99,763, Apr. 29, 1959. This application Nor. 13, E61, Ser. No. 151,736

15 Claims. (ill. 193-137) This invention relates generally to rotary sheet-fed printing presses having printing units comprising three cylinders. In particular, it relates to a novel arrangement of these cylinders in a printing unit, and to such arrangement embodied in a multicolor rotary press of known construction.

This application is a continuation of United States application Serial No. 809,763, filed April 29, 1959, now abandoned.

Printing units of the above type include an impression cylinder, an ink transferring cylinder located generally vertically above and spaced from the impression cylinder, and a printing cylinder between and adapted to coast with both the ink transferring and impression cylinders. The printing cylinder has previously been customarily located on that side of a plane passing through the other two cylinders away from the feeding end of the press. This type of unit has been conventional for a number of years in most lithographic printing presses. In such a press, the ink transferring cylinder is a plate cylinder, and the printing cylinder is a blanket cylinder.

It is the usual practice in operating one of the above presses to sequentially move the blanket cylinder into and out of contact with the other two cylinders by first moving the blanket cylinder into engagement with the plate cylinder and next with the impression cylinder when printing pressure is thrown on, and to move it out of contact with the plate cylinder and then out of contact with the impression cylinder when the pressure is thrown ofi. Each of the three cylinders is provided with a circumferential gap which usually occupies between 60 and 100 of the periphery of the cylinder. The gaps are timed to come adjacent each other at the nip of the respective cylinders, and therefore the blanket cylinder gap will coincide with the plate cylinder and impression cylinder gaps at different times of each press cycle. Several types of throwoff mechanism, for example the one described in US. Patent 2,773,445 to I. R. Wood, have been designed to effect the sequential throwing off and on of the blanket or printing cylinder with respect to the other two cylinders. The throwofi mechanism functions to cause the separation or engagement of the cylinders during the time when the gaps are facing each other so that the last sheet before a press trips off is completely printed, and further, so that the first sheet receives a full charge of ink from the printing cylinder to effect a full, even print on the first sheet from the leading to the trailing edge thereof when recommencing printing.

One type of lithographic press embodying such a printing unit is shown in US. Patent 2,707,914 to C. W. Harrold. This press utilizes double-diameter transfer cylinders between the impression cylinders of adjacent units.

The main purpose of the large transrer cylinders is to provide a fairly large arcuate surface which minimizes smudging of the print against the cylinder when engaged by the freshly printed side of a sheet. While a multicolor press of the type shown in the Harrold patent has been widely accepted and performs very satisfactorily, the space for operator access between the adjacent units is somewhat limited because of the particular way in which the cylinders of the printing units have been arranged. One attempted solution to this space problem is found in Harrold US. Patent 2,554,904 which shows a fanned-out arrangement of units. This solution has never gone into use, however, because of the increased manufacturing cost in making each of the side frames of a multicolor press different than the rest of the side frames.

The particular arrangement of the cylinders of a unit as described in the aforementioned patents contributes to the occasional formation of print disturbances caused by momentary shock in the gear train of the press. These disturbances are created by the passage of the gaps at their leading and trailing edges. For example, as the printing surface of the blanket cylinder of a lithographic press comes into engagement with the leading edge of a sheet on the impression cylinder, a momentary shock occurs as a result of the necessary printing pressure setting between the two cylinders. The shock will create a disturbance outwardly along a general line through the axes of the two cylinders, and thus will be transferred in part to the gears of the blanket and plate cylinders, which are at that time in image-transferring engagement. The shock will, unless the entire gearing and supporting system for the cylinders is completely free of backlash or play, impart a momentary motion to the blanket cylinder gear in a direction reverse to the direction of rotation of the plate cylinder gear which it is driving.

It is a principal object of this invention to provide a three-cylinder printing unit arrangement which overcomes the aforementioned difficulties.

It is another object of the invention to provide added space between the units of a multicolor printing press which utilizes double size transfer cylinders between the units, without changing the length of the press or varying the positions of the cylinders from one unit to the next.

It is still another object of the invention to eliminate or minimize print disturbances caused by shock in the gear train of a printing unit of the general type described.

A still further object of the invention is to provide a printing unit cylinder arrangement which, when used in conjunction with a double-size delivery cylinder, enables slitting of sheets on the impression cylinder after the last impression has been made.

Other objects and advantages will be apparent from the following description in which reference is made to the accompanying drawing.

he drawing illustrates a fragmentary side elevational view of certain portions of a printing press embodying certain aspects of the invention.

Referring now to the drawing in detail, a sheet is fed from right to left down an inclined feed table it) by conventional drive tapes (not shown). The sheet is front and side registered while resting on the feed table and is then advanced in registered position to a feed cylinder l1 having grippers 12. The grippers l2 transfer the sheet to grippers 13 of an advance cylinder 14 and from there to grippers 15 on an impression cylinder 16 of a first printing unit. The sheet is printed between the impression cylinder 16 and a cooperating blanket cylinder 17 having an image on a conventional rubber blanket. F or purposes of illustration only, the press shown is a lithographic print ing press. Obviously, however, certain aspects of the invention will be seen to be applicable to other types of presses embodying a three-cylinder printing unit.

From the grippers 15 of the impression cylinder 16, the sheet which now has the first color printed thereon is given up to grippers on a transfer cylinder 18, and from there to alternate impression and transfer cylinders until it passes completely through the printing portion of the press. One color is printed by each unit in registration with all the others. The grippers on the last impression l and impression cylinders.

cylinder in transfer the sheet to grippers 19 mounted on each of several gripper assemblies 29 carried on spaced, continuous chains 21 of a sheet delivery 22. The sheet is taken by one of the gripper assemblies to a position over a delivery pile (not shown), at which point it is released to drop onto the top of the pile. The chains 21 travel around sprockets 23 carried at the ends of a delivery cylinder 24 The delivery cylinder 24 and the various transfer cylinders 18 are preferably twice the diameter of the remaining cylinders of the press, but may be any multiple thereof if desired. The transfer cylinders 18 therefore necessarily have two sets of grippers which are spaced 180 apart, and the delivery cylinder receives a different gripper assembly each 180 about that cylinder.

Each printing unit of the lithographic press shown comprises the impression cylinder 16, the blanket cylinder 17, a plate cylinder 25, an inker 26 and a dampening unit 27. The plate cylinder 25 carries the usual lithographic plate which receives ink from the inker and transfers it to the blanket on the blanket cylinder 17. The inker 26 and the dampening unit 27 may be of any conventional type, but it is preferred that the entire inker be located generall over the plate cylinder, and that the dampening unit 27 be relatively narrow in a horizontal direction.

It will be noted that the blanket cylinder is located toward the feeding end of the press relative to the impression cylinder 16 and the plate cylinder 25. I have found is location to provide substantial benefits in providing more access between adjacent printing units, and a substantial elimination of print disturbances.

Regarding the increased operator access, it will be noted that between each pair of adjacent units, a section 28 of a platform 29 may be hinged and movable between upper inoperative and lower operative positions. The upper position shown in dotted lines lies in the area normally occupied by the blanket cylinders of a press of the type shown in the aforementioned l-larrold patents. By placing the blanket cylinders in the positions shown in the drawings, they now occupy space directly below the dampening units 27. The units are therefore considerably more compact in a horizontal direction.

Nested eccentrics 39 produce the sequential throwoif and throwon of the blanket cylinder relative to the plate The aforementioned WVood patent illustrates mechanism capable of accomplishing these results. The throwoif mechanism is shown in these drawings simply as outer eccentrics 31 journaled in the frame and inner eccentrics 32 journaled in the outer eccentrics. The inner eccentrics may be rigidly connected to a shaft 33 of the blanket cylinder 17 or may be interconnected by a shaft outside and around the cylinders. The throwolf mechanism is preferably designed to rotate both the inner and outer eccentrics 32 and 31 simultaneously to effect a movement of the blanket cylinder away from the plate cylinder and then to rotate only the inner eccentrics 32 through a further angle to effect movement of the blanket cylinder out of contact with the impression cylinder 16 during the throwoff movement. Operation of the eccentrics in the same sequence in a reverse direction will cause a throwon movementfirst to the plate cylinder and then to the impression cylinder during the time when the gaps coincide.

I have found that I can completely eliminate, or at least minimize in most cases, the print disturbances which might occur in the type of press shown in the Harrold patents. In each type of printing unit, with the blanket cylinder located on the opposite side of a plane passing through the impression and plate cylinders from that illustrated herein, as the printing surfaces engage during each revolution of the cylinders immediately after the gaps have passed between the impression and blanket cylinders, there would occur a momentary shock because of the required printing pressure necessary to effect transfer of the printed image from the blanket to the paper sheet held by the grippers on the impression cylinder. This is capable of creating a force which acts upon the blanket cylinder in a direction opposite to the direction of rotation of that cylinder, and would therefore cause a disturbance between the blanket cylinder and the plate cylinder gears if the slightest degree of backlash was present between the gears. This disturbance could cause the plate cylinder and blanket cylinder gears to have a momentary relative motion in opposite directions which in turn would smudge the image as it is being transferred to the blanket cylinder at that point.

By relocating the position of the blanket cylinder toward the feed end of the press rather than the delivery end, as was formerly done, the shock, if any, now occurs in the direction along a line through the axes of the impression and blanket cylinders generally toward the feeder end of the press rather than the delivery end, and is therefore in the same eneral direction as the direction of rotation of the blanket cylinder. Consequently, instead of causing any momentary backlash between the gears of the blanket and plate cylinders, the shock is transferred to the blanket cylinder gears in the direction of rotation at all times. This prevents relative motion between these cylinders at the time the shock occurs.

The double-size delivery cylinder 24 has pronounced benefits in reducing smudging of a freshly printed sheet. This particular kind of delivery cylinder is described and claimed in the co-pending US. application of H. A. Pritchard, Serial No. 756,357, filed August 21, 1958, now US. Patent No. 2,940,387. size delivery cylinder with the arrangement of cylinders of the Harrold patents would prevent me from slitting sheets on the impression cylinder in of the last printing unit, since there would be no room between tie blanket cylinder and the delivery cylinder 24'- for a slitting wheel and its mounting head. Now, simply by positioning the blanket cylinder as shown in the drawing, access to the impression cylinder is provided for a slitting wheel 34 and its support (not shown). The slitting wheel 34 may be of any conventional type and usually cooperates with a hardened steel band which is wrapped around the last impression cylinder. a

While the invention is particularly useful in a lithographic printing press, it has similar advantages also in a so-called wrap-around letterpress in which the space occupied by the blanket cylinder herein is occupied by a plate cylinder of such letterpress, and in which the space herein occupied by the plate cylinder is occupied by a large inking drum of the inker. it is customary in presses of both these types to provide conventional bearers between :the cylinders 17 and 25. These bearers are located at the ends of the cylinders and are urged toward each other with a preselected pressure force to maintain substantial rigidity of the printing units.

Various modifications may be made in the details of construction and in the type of printing press with which the invention is used without departing from the spirit and scope of the invention.

Having described my invention, I claim:

1. A rotary, sheet-fed lithographic printing press comprising a plurality of horizontally spaced like printing units each of which comprises impression, blanket and plate cylinders arranged with the plate cylinder substantially vertically above the impression cylinder and the blanket cylinder mounted on the approaching side of a plane passing through the impression and plate cylinders, all of said cylinders being of the same diameter and having corresponding gaps in their surfaces, a transfer cylinder cooperating with each pair of adjacent impression cylinders, a delivery cylinder having chain sprockets at its ends, an endless chain conveyor traveling around said sprockets, a plurality of sheet gripper assemblies on said conveyor adapted to travel around said delivery cylinder, receive sheets from the last impression cylinder, and transport them to a delivery station, said transfer cylintiers and delivery cylinder being twice the size of the cyl- The utilization of a doubleinders of the printing units and having their axes in a common horizontal plane a distance below the axes of the impression cylinders such that the tops of the impression, transfer and delivery cylinders are approximately at the same horizontal level, a gear train comprising a gear on each cylinder in mesh with its cooperating cylinders, and means for driving said gear train.

2. The invention set forth in claim 1 wherein each printing unit comprises an inker having rollers cooperating with the plate cylinder and located thereabove, means for applying a plate dampening solution to a plate on the plate cylinder prior to its being contacted by the inking means, said dampening means being located generally vertically above the blanket cylinder, and a horizontal platform above and closely adjacent each transfer cylinder and the delivery cylinder.

3. The invention set forth in claim 2 wherein a slitting wheel and its mounting means is mounted to cooperate with the last impression cylinder between its nip with the cooperating blanket cylinder and a point at which sheets are transferred to the gripper assemblies passing around the delivery cylinder.

4. A rotary lithographicprinting press comprising a plurality of horizontally spaced printing units each having the cylinders thereof in the same relative positions and of the sme diameters; each of said printing units comprising an impression cylinder mounted for rotation on a fixed horizontal axis, sheet grippers carried by said impression cylinder and mounted in a gap in the periphery thereof, a gear mounted on an end of said impression cylinder, means for driving said gear in a given direction to carry a sheet held by the grippers through a printing zone, a blanket cylinder having a gap corresponding to the gap in the impression cylinder and adapted to have a blanket mounted on its surface for pressure contact with a sheet held by the grippers of the impression cylinder as the sheet passes through the printing zone, a gear on said blanket cylinder in mesh with and driven by the gear on the impression cylinder, a plate cylinder mounted for rotation on a fixed axis and being adapted to have a lithographic plate mounted on its surface for pressure contact with the blanket on the blanket cylinder, said plate cylinder having a gap corresponding to the gaps in the blanket and impression cylinders, a gear on said plate cylinder meshing with and driven by the gear on the blanket cylinder, said blanket cylinder being mounted with respect to the impression and plate cylinders with the printing zone being on the approaching side of a plane passing through the axes of the impression and plate cylinders, means mounting the blanket cylinder for relative bodily movement into and out of contact with the impression and plate cylinders, said plate cylinder being disposed substantially vertically above the impression cylinder, inking means for contacting a plate on the plate cylinder and located thereabove, and means for applying a plate dampening solution to a plate on the plate cylinder prior to being contacted by the inking means, said dampening means being located generally vertically above a portion of the blanket cylinder, and a transfer cylinder between each pair of adjacent impression cylinders, each transfer cylinder being twice the diameter of an impression cylinder.

5. The invention set forth in claim 4 wherein all of said transfer cylindershave their axes in a common horizontal plane located a distance below a common horizontal plane passing through the axes of the impression cylinders such that the tops of the impression and transfer cylinders are approximately at the same level.

6. The invention set forth in claim 5 wherein a delivery cylinder is mounted to receive sheets from the impression cylinder of the last printing unit, said delivery cylinder being the same size and located in the same horizontal plane as said transfer cylinders, and a sheet slitter uni-t cooperating with the last impression cylinder between 6 the printing zone thereof and a point at which sheets are tran ferred to the delivery cylinder.

7. A rotary lithographic printing press comprising a plurality of horizontally spaced printing units each having the cylinders thereof in the same relative positions and of the same diameters; each of said printing units comprising an impression cylinder mounted for rotation on a fixed horizontal axis, sheet grippers carried by said impression cylinder and mounted in a gap in the periphery thereof, a gear mounted on an end of said impression cylinder, means for driving said gear in a given direction to carry a sheet held by the grippers through a printing zone, a blanket cylinder having a gap corresponding to the gap in the impression cylinder and adapted to have a blanket mounted on its surface for pressure contact wtih a sheet held by the grippers of the impression cylinder as the sheet passes through the printing zone, a gear on said blanket cylinder in mesh with and driven by the gear on the impression cylinder, a plate cylinder mounted for rotation on a fixed axis and being adapted to have a lithographic plate mounted on its surface for pressure contact with the blanket on the blanket cylinder, said plate cylinder having a gap corresponding to the gaps in the blanket and impression cylinder, a gear on said plate cylinder meshing with and driven by the gear on the blanket cylinder, said blanket cylinder being mounted with respect to the impression and plate cylinders with the printing zone being on the approaching side of a plane passing through the axes of the impression and plate cylinders, means mounting the blanket cylinder for relative bodily movement into and out of contact with the impression and plate cylinders, said plate cylinder being disposed substantially vertically above the impression cylinder, inking means for contacting a plate on the plate cylinder and located thereabove, and means for applying a plate dampening solution to a plate on the plate cylinder prior to its being contacted by the inking means, said dampening means being located generally vertically above a portion of the blanket cylinder; and transfer cylinder means between each pair of adjacent impression cylinders.

8. A rotary lithographic printing press comprising a plurality of horizontally spaced printing units each having the cylinders thereof in the same relative positions and of the same diameters; each of said printing units comprising a rotatable impression cylinder, sheet grippers carried by said impression cylinder and mounted in a gap in the periphery thereof, a gear mounted on an end of said impression cylinder, means for driving sa'd gear in a given direction to carry a sheet held by the grippers through a printing zone, a rotatable blanket cylinder having a gap corresponding to the gap in the impression cylinder and adapted to have a blanket mounted on its surface for pressure contact with a sheet held by the grippers of the impression cylinder as the sheet passes through the printing zone, a gear on said blanket cylinder in mesh with and driven by the gear on the impression cylinder, a rotatable plate cylinder adapted to have a lithographic plate mounted on its surface for pressure contact with the blanket on the blanket cylinder, said plate cylinder having a gap corresponding to the gaps in the blanket and impression cylinders, a gear on said plate cylinder meshing with and driven by the gear on the blanket cylinder, said blanket cylinder being mounted with respect to the impression and plate cylinders with the printing zone being on the approaching side of a plane passing through the axes of the impression and plate cylinders, said plate cylinder being disposed substantially vertically above the impression cylinder, inking means for contacting a plate on the plate cylinder and located thereabove, and means for applying a plate dampening solution to a plate on the plate cylinder prior to its being contacted by the inking means, said dampening means being located generally vertically above a portion of the blanket cylinder; and a transfer cylinder between each pair of adjacent impression cylinders, each transfer cylinder having a diameter which is an even multiple of the diameter of an impression cylinder arid having separate sets of sheet grippers equally spaced circumferentially thereabout a distance corresponding to the circumference of each impression cylinder.

9. A rotary lithographic printing press comprising a plurality of horizontally spaced printing units each having the cylinders thereof in the same relative positions and of the same diameters; each of said printing units comprising an impression cylinder mounted for rotation on a fixed horizontal axis, sheet grippers carried by said impression cylinder and mounted in a gap in the periphery thereof, said grippers being adapted to receive sheets one at a time and carry them through a printing zone, a blanket cylinder having a gap corresponding to the gap in the impression cylinder and adapted to have a blanket mounted on its surface for pressure contact With a sheet held by the gripers of the impression cylinder as the sheet passes through the printing zone, a plate cylinder mounted for rotation on a fixed axis and being adapted to have a lithographic plate mounted on its surface for pressure contact with the blanket on the blanket cylinder, said plate cylinder having a gap corresponding to the gaps in the blanket and impression cylinders, said blanket cylinder being mounted With respect to the impression and plate cylinders with the printing zone being on the approaching side of a plane passing through the axes of the impression and plate cylinders, means mounting the blanket cylinder for relative bodily movement into and out of contact with the impression and plate cylinders, said plate cylinder being disposed substantially vertically above the impression cylinder, inkingmeans for contacting a plate on the plate cylinder and located thereabove, and means for applying a plate dampening solution to a plate on the plate cylinder prior to its being contacted by the inking means, said dampening means being located generally vertically above a portion of the blanket cylinder and to one side of the plate cylinder, the horizontal depth of the plate cylinder and dampening means defining the top of a space having vertical sides and Within which the blanket cylinder Wholly lies, a transfer cylinder between each pair of adjacent impression cylinders, each transfer cylinder being twice the diameter of an impression cylinder and having sheet grippers spaced circumferentially 180 apart thereon, and means for driving all of said cylinders at the same surface speeds.

10. A rotary lithographic printing press comprising a plurality of horizontally spaced printing units each having the cylinders thereof in the same relative positions and or". the same diameters; each of said printing units comprising a rotatable impression cylinder, sheet grippers mounted on said impression cyil d r for carrying a sheet held by the grippers through a printing zone, a rotatable blanket cylinder adapted to have a blanket mounted on its surface for pressure contact with a sheet held by the impression cylinder grippers as the sheet passes through the printing zone, a rotatable plate cylinder adapted to have a lithographic plate mounted on its surface for pressure contact with the blanket on the blanket cylinder, said blanket cylinder being mounted with respect to the impression and plate cylinders With the prin zone being on the approaching side of a plane passing through the axes of the impression and plate cylinders, said plate cylinder being disposed substantially vertically above Lil impression cylinder, inking means above the plate cylinder, and means for applying a plate dampening solution to a plate on the plate cylinder prior to its being contacted by the inking means, said darnpenim means being located generally vertically above a portion of the blanket cylinder; a transfer cylinder between each pair of adjacent impression cylinders, each transfer cylinder being a diameter which is an even multiple of the diameter of an impression cylinder and having separate sets of sheet grippers equally spaced circumfercntially thereabout a distance corresponding to the circumference of each impression cylinder, and means for driving all of said cylinders at the same surface speeds.

ll. A rotary lithographic printing press comprising a plurality of horizontally spaced printing units each having the cylinders thereof in the same relative positions and of the same diameters; each of said printing units comprising a rotatable impression cylinder, sheet grippers mounted on said impression cylinder for carrying a sheet held by the grippers through a printing zone, a rotatable blanket cylinder adapted to have a blanket mounted on its surface for pressure contact with a sheet held by the impression cylinder grippers as the sheet passes through the printing zone, a rotatable plate cylinder adapted to have a lithographic plate mounted on its surface for pressure contact With the blanket on the blanket cylinder, said blanket cylinder being mounted respect to the impression and plate cylinders with the printing zone being on the approaching side of a plane passing through the axes of the impression and plate cylinders, said plate cylinder being disposed substantially vertically above the impression cylinder, inking means above the plate cylinder, and means for applying a plate dampening solution to a plate on the plate cylinder prior to its being contacted by the inking means, said dampening means being located generally vertically above a portion of the blanket cylinder and to one side of the plate cylinder, the horizontal depth of the plate cylinder and dampening means defining the top of a space having ertical sides and Wi in Which the blanket cylinder Wholly lies; a transfer cylinder between each pair of adjacent impression cylinders, each transfer cylinder being twice the diameter of an impression cylinder and having sheet grippers spaced circumferentially apart thereon, and means for drivin" all of said cylinders at the same surface speeds.

12. in a rotary printing press comprising a plurality of horizontally spaced printing units each having the cylinders thereof in the same relative positions and of the same diameters; each of said printing units comprising an impression cylinder mounted for rotation on a fixed horizontal axis, sheet grippers carried by said impression cylinders and mounted in a gap in the periphery thereof, a gear mounted on an end of said impression cylinder, means for driving said gear in a given direction to carry a sheet held by the grippers through a printing zone, a printing cylinder having a gap corresponding to the gap in the impression cylinder and adapted to have a printing member mounted on the surface for pressure contact with a sheet held by the grip ers of the impression cylinder as the sheet passes through the printing zone, a gear on said printing cylinder in mesh with and driven by the gear on the impression cylinder, an ink-transferring cylinder mounted for rotation on a fixed axis and adapted to run in pressure contact W'th the printing cylinder, said ink-transferring cylinder having a gap corresponding to the gaps in the printing and impression cylinders, a gear on said inlotransferring cylinder meshing with and driven by the gear on the prlimg cylinder, and said ink-transferring cylinder being disposed substantially vertically above the impression cylinder, said printing cylinder being mounted with respect to the impression and ink-transferring cylinders to dispose the printing zone on the approaching side or" a plane passing through the axes of the impression and inktransferring cylinders, means mounting the printing cylinder for relative bodily movement into and out or" contact with the impression and ink-transferring cyl nders, and means for inking the ink-transferring cylinder; a transfer cylinder between each pair of adjacent impression cylinders, each transfer cylinder being twice the diameter or" an impression cylinder and being located such that the upper peripheries of the impression and transfer cylinders are approximately at the same level; a delivery cylinder mounted to receive sheets from the impression cylinder of the last printing unit, said delivery cylinder being the same size and located in the same horizontal plane as each transfer cylinder; and sheet slitting means cooperating with the last impression cylinder between the printing zone and point at which sheets are transferred to the delivery cylinder.

13. I11 a rotary printing press comprising a printing unit having an impression cylinder mounted for rotation on a fixed horizontal axis, sheet grippers carried by said impression cylinder and mounted in a gap in the periphery thereof, means for driving said impression cylinder to carry a sheet held by the grippers through a printing zone, a printing cylinder having a gap corresponding to the gap in the impression cylinder and adapted to have a printing member mounted on its surface for pressure contact with a sheet held by the grippers of the impression cylinder as the sheet passes through the printing zone, an ink-transferring cylinder mounted for rotation on a fixed axis and adapted to run in pressure contact with the printing cylinder, said cylinders being of substantially the same diameter, said ink-transferring cylinder having a gap corresponding to the gap in the printing and impression cylinders and being disposed substantially vertically above the impression cylinder, said printing cylinder being mounted with respect to the impression cylinder and ink-transferring cylinder to dispose the printing zone on the approaching side of the plane passing through the axes of the impression and ink-transferring cylinders, means mounting the printing cylinder for bodily movement into and out of contact with the impression and ink-transferring cylinders, means for inking the inktransferring cylinder, delivery mechanism for delivering printed sheets from the press including a delivery cylinder mounted to receive sheets from said impression cylinder, said delivery cylinder having the upper periphery thereof at substantially the same level as the upper periphery of said impression cylinder and having a diameter substantially twice that of said impression cylinder, and a sheet slitting means cooperating with said impression cylinder between the printing zone and the point at which sheets are transferred from said impression cylinder to said delivery cylinder.

14. In a rotary printing press comprising a printing unit having a rotatable impression cylinder, sheet grippers carried by said impression cylinder, means for driving said impression cylinder to carry a sheet held by the grippers through a printing zone, a printing cylinder adapted to have a printing member mounted on its surface for pressure contact with a sheet held by the grippers of the impression cylinder as the sheet passes through the printing zone, a rotatable ink-transferring cylinder adapted to run in pressure contact with the printing cylinder, said cylinders being of substantially the same diameter rotating at the sarne peripheral speed, said ink-transferring cylinder being disposed substantially vertically above the impression cylinder and said printing cylinder being mounted with respect to me impression cylinder and ink-transferring cylinder to dispose the printing zone on the approaching side of the plane passing through the axes of the impression and ink-transferring cylinders, delivery mechanism for delivering printed sheets from the press including a delivery cylinder mounted to receive sheets from said impression cylinder, said delivery cylinder having the upper periphery thereof at substantially the same level as the upper periphery of said impression cylinder, and sheet slitting means co-operating with said impression cylinder between the printing zone and the point at which sheets are transferred from said impression cylinder to said delivery cylinder.

15. In a rotary printing press, the structure as defined in claim 14, wherein said delivery cylinder is of a diameter twice that of said impression cylinder.

References Cited in the file of this patent UNITED STATES PATENTS 1,874,613 Kaddeland Aug. 30, 1932 2,554,904 Harrold May 29, 1951 2,707,914 Harrold May 10, 1955 2,767,790 Jacobson et al ct. 23, 1956 FOREIGN PATENTS 783,983 Great Britain Oct. 2, 1957 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 3,112,695 December 3 1963 Howard J, Seel It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 6, line 24, for "cylinder" read cylinders column 8, line 17, after "mounted" insert with Signed and sealed this 23rd day of June 1964.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. A ROTARY, SHEET-FED LITHOGRAPHIC PRINTING PRESS COMPRISING A PLURALITY OF HORIZONTALLY SPACED LIKE PRINTING UNITS EACH OF WHICH COMPRISES IMPRESSION, BLANKET AND PLATE CYLINDERS ARRANGED WITH THE PLATE CYLINDER SUBSTANTIALLY VERTICALLY ABOVE THE IMPRESSION CYLINDER AND THE BLANKET CYLINDER MOUNTED ON THE APPROACHING SIDE OF A PLANE PASSING THROUGH THE IMPRESSION AND PLATE CYLINDERS, ALL OF SAID CYLINDERS BEING OF THE SAME DIAMETER AND HAVING CORRESPONDING GAPS IN THEIR SURFACES, A TRANSFER CYLINDER COOPERATING WITH EACH PAIR OF ADJACENT IMPRESSION CYLINDERS, A DELIVERY CYLINDER HAVING CHAIN SPROCKETS AT ITS ENDS, AN ENDLESS CHAIN CONVEYOR TRAVELING AROUND SAID SPROCKETS, A PLURALITY OF SHEET GRIPPER ASSEMBLIES ON SAID CONVEYOR ADAPTED TO TRAVEL AROUND SAID DELIVERY CYLINDER, RECEIVE SHEETS FROM THE LAST IMPRESSION CYLINDER, AND TRANSPORT THEM TO A DELIVERY STATION, SAID TRANSFER CYLINDERS AND DELIVERY CYLINDER BEING TWICE THE SIZE OF THE CYLINDERS OF THE PRINTING UNITS AND HAVING THEIR AXES IN A COMMON HORIZONTAL PLANE A DISTANCE BELOW THE AXES OF THE IMPRESSION CYLINDERS SUCH THAT THE TOPS OF THE IMPRESSION, TRANSFER AND DELIVERY CYLINDERS ARE APPROXIMATELY AT THE SAME HORIZONTAL LEVEL, A GEAR TRAIN COMPRISING A GEAR ON EACH CYLINDER IN MESH WITH ITS COOPERATING CYLINDERS, AND MEANS FOR DRIVING SAID GEAR TRAIN. 